<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        var num1 = prompt('请输入第一个数:');
        var num2 = prompt('请输入第二个数:');

        function getMax(num1, num2) {
            if (num1 > num2) {
                return num1;
            } else {
                return num2;
            }
        }
        var re = getMax(num1, num2);
        alert('两个数的最大值是：' + re);
    </script>
</body>

</html>